JP5634699B2 - Glass defect source identification method, molten cast refractory, and glass melting furnace using the same - Google Patents

Description

  The present invention relates to a glass defect generation source identifying method, a molten cast refractory, and a glass melting furnace using the same, which are used when manufacturing a glass product using a glass melting furnace, and more particularly, molten casting into molten glass. The present invention relates to a glass defect generation source specifying method capable of directly specifying a glass defect caused by elution of a refractory component, a molten cast refractory suitable for the method, and a glass melting furnace.

  In general, the main commercially available glasses are classified according to composition, soda glass, aluminosilicate glass, borosilicate glass and the like. These glasses are used as materials when manufacturing glass products. After melting the glass material in a glass melting kiln lined with a furnace material made of refractory industrially, the molten glass material is molded. Then, it is cooled and gradually cooled to solidify it into a glass product.

  As the refractory, a molten cast refractory obtained by melting a refractory raw material of a predetermined composition completely in an electric furnace, pouring it into a mold of a predetermined shape, gradually cooling to room temperature, and re-solidifying is used. Yes. This refractory is a refractory having a high corrosion resistance because it is completely different from the structure and manufacturing method of a bonded refractory that is formed by firing a powdery or granular raw material into a predetermined shape and fired or remains unfired.

  Typical examples of such molten cast refractories include alumina / zirconia / silica fused cast refractories, alumina melt cast refractories, zirconia melt cast refractories, and the like. For example, an alumina / zirconia / silica fused cast refractory is generally called by the name of AZS fused cast refractory and is widely used as a refractory for melting glass.

The AZS molten cast refractory consists of approximately 80-85% (mass%, the same unless otherwise specified) crystal phase and 15-20% matrix glass phase filling the crystal gap. The crystal phase is composed of corundum crystals and badelite crystals, and the composition thereof is commercially available. Al ₂ O ₃ is 45 to 52%, ZrO ₂ is 28 to 41%, and SiO ₂ is 12 to 16%. %, Na ₂ O is about 1 to 1.9%.

As is well known, ZrO ₂ has a transformation expansion due to a monoclinic and tetragonal phase transition around 1150 ° C. when the temperature is raised and 850 ° C. when the temperature is lowered, and exhibits abnormal shrinkage and expansion. The matrix glass phase acts as a cushion between crystals and absorbs the stress caused by transformation expansion due to the transition from tetragonal to monoclinic zirconia in the production of AZS molten cast refractories. It plays an important role for manufacturing without cracks.

  However, since this molten cast refractory is always exposed to a high temperature during its use, the contact portion with the molten glass material is eroded, and at that time, the matrix glass phase oozes out into the molten glass material (glass). A phenomenon called exudation occurs. This glass leaching phenomenon is considered to occur because the viscosity of the matrix glass phase is lowered and fluidity is caused at high temperature, and it is extruded by the force of gas released from the AZS molten cast refractory at high temperature. .

  The composition of the glass that exudes to the surface of the refractory is a highly viscous glass rich in alumina and zirconia, so when mixed in the mother glass, it does not completely diffuse into the melting glass and becomes extraneous. It becomes a glass defect called a streak.

  This glass defect is a serious industrial problem because it reduces the yield of the product. Therefore, the yield is improved by specifying the location where the glass defect occurs and selecting the operation conditions such as appropriate temperature operation and the furnace material to be used.

  However, the appearance situation of this glass defect has individual characteristics depending on each melting kiln, and further varies depending on the operating conditions and the like, so the occurrence situation takes a complicated form. Therefore, in order to prevent the occurrence of such glass defects, conventionally, the generation source is specified and the structure and operating conditions of the glass melting furnace are determined using a mathematical simulation.

  As a method based on this mathematical simulation, for example, in a glass melting furnace having a plurality of glass melt flow paths (lines), when melting defects are concentrated on a specific line, a large number of particles are present on the problem line. There is known a particle trajectory method in which the source is traced back in time, the trajectory of the particle is traced, and the source is estimated from the streamline.

  As an improvement of this particle trajectory method, the flow field of the glass melt in the glass melting furnace is obtained, and a virtual tracer component is generated at the outlet to a specific flow path for the flow field, thereby glass melting. Establishing an advection diffusion equation that considers only the advection related to the tracer component in the liquid flow field, and the concentration distribution of the tracer component obtained by solving this advection diffusion equation in the reverse time direction, the inflow probability of the tracer component to a specific channel A method is known in which the distribution is obtained and the position of the source of the dissolution defect is specified based on the distribution (see Patent Document 1).

  Moreover, although the generation | occurrence | production source of a glass fault is not specified, the fusion | melting cast refractory containing SrO, BaO, ZnO is known as a refractory used for a melting furnace (refer patent documents 2-4).

JP 2000-7342 A Japanese Patent No. 2870188 Japanese Patent No. 4297543 JP 2001-220249 A

  However, the location of the source of knots and streaks by the above-mentioned mathematical simulation is to analyze the flow of the glass melt and introduce particles and components that become tracers in the flow to determine the probability of the inflow location of the source. Therefore, there is a problem that the operation is complicated. In addition, since this mathematical simulation indirectly specifies the source, there is a problem that the accuracy is low. For this reason, even if the problem of the place presumed to be a generation source is removed, the occurrence of glass defects may not change.

  Therefore, the present invention has been made to solve the above-described problems, and provides a method for identifying a glass defect source that can directly identify the glass defect source without using a mathematical simulation. It is intended to do.

The glass defect generation source identifying method of the present invention includes a step of constructing a glass melting furnace using the molten cast refractory of the present invention as a lining furnace material, melting a glass material by the glass melting furnace, And a step of producing a glass product by pouring into a mold, and a step of extracting a glass product having a glass defect and analyzing a component composition to determine a position of a glass defect generation source of the glass melting kiln. It is characterized by this.

  Typical examples of the lining furnace material used at this time include alumina / zirconia / silica fusion cast refractories, alumina fusion cast refractories and zirconia fusion cast refractories.

The alumina / zirconia / silica fusion cast refractory of the present invention has a chemical composition of mass%, Al ₂ O ₃ of 45 to 70%, ZrO ₂ of 14 to 45%, SiO ₂ of 9 to 15%, Na ₂ The total amount of O, K ₂ O, Cs ₂ O and SrO is 2% or less, and contains 0.2 to 2% of at least one tracer component selected from Cs ₂ O and SrO It is what.

Zirconia fused cast refractory of the present invention is a chemical composition by mass%, comprises ZrO ₂ 88 to 97%, the SiO ₂ from 2.4 to 10.0%, the Al ₂ O ₃ 0.4 to 3% The total amount of Na ₂ O, K ₂ O and Cs ₂ O is 1% or less, and contains 0.2 to 0.5% of the tracer component of Cs ₂ O. .

Further, the glass melting furnace of the present invention is characterized by using at least one of fused cast refractories selected from alumina-zirconia-silica fusion cast refractory Mono及 beauty zirconia fused cast refractory of the present invention Is.

According to the glass defect generation source specifying method of the present invention, a molten cast refractory material having a predetermined composition and containing a tracer component is used as a lining furnace material of a glass melting kiln. It can be easily and directly specified whether it becomes a defect generation source.

  The molten cast refractory of the present invention and the glass melting furnace using the same are suitable for the glass defect generation source identifying method of the present invention.

  First, the glass defect generation source specifying method of the present invention will be described.

In this glass defect generation source identifying method, first, glass melting using a molten cast refractory containing at least one tracer component selected from Cs ₂ O, SrO, BaO and ZnO as a lining furnace material of a glass melting furnace. Build a kiln. At this time, what contains the said tracer component is provided in a contact location with the molten glass of a lining furnace material.

At this time, the molten cast refractory used as the lining furnace material of the glass melting furnace contains at least one tracer component selected from Cs ₂ O, SrO, BaO and ZnO, and is fused with alumina, zirconia, siliceous. Typical examples include a cast refractory, an alumina melt cast refractory, or a zirconia melt cast refractory.

  And when this molten cast refractory containing the tracer component is used to construct a glass melting kiln, when one type of molten cast refractory is used, a part of the glass melting kiln that may cause a glass defect. Used to configure. This is because if it is used for everything, it will become impossible to specify the source. At this time, a conventionally used molten cast refractory that does not contain a tracer component may be used in a portion that has no possibility as a glass defect source.

Further, when two or more types of molten cast refractories containing a tracer component are used, a possible portion as a glass defect generation source is constructed by a molten cast refractory having different tracer components. Here, the different tracer components are different in the case where Cs ₂ O, SrO, BaO and ZnO are used singly, and when these components are combined to form a tracer component. Means different types and / or content ratios of the contained tracer components, which can be distinguished from each other in the composition analysis described later.

  Therefore, as the glass melting furnace used here, it is preferable to divide the glass melting furnace into arbitrary block units and to use molten cast refractories having different tracer components for each block unit.

  Then, the glass material is melted in the constructed glass melting kiln, and the molten glass material is moved while being melted in the furnace in the same manner as in the production of a normal glass product, molded at a predetermined location, and cooled. , Solidify to produce the desired glass product.

  Next, it is confirmed whether or not a glass defect has occurred in the obtained glass product, a glass defect is extracted, and the extracted glass product is analyzed for the component composition of the glass in the defective portion. This composition analysis can be performed by electron microscope analysis (SEM-EDX, EPMA), fluorescent X-ray analysis, atomic absorption method, ICP (inductively coupled plasma) emission analysis, ICP mass spectrometry, and the like. At this time, the tracer component contained in the molten cast refractory is preferably 0.2% or more so that the tracer component can be sufficiently detected.

  As a result of the analysis, it is possible to identify the glass defect generation source of the glass melting furnace by analyzing whether or not the tracer component is contained, and if so, which tracer component is contained. . That is, the source of the glass defect is easily and directly specified as the location using the lining furnace material containing the tracer component detected by analysis. In the composition analysis, the glass material used, the presence or absence of the tracer component, and the content of the tracer component must be considered.

  First, the case where the used glass material does not contain a tracer component will be described. In this case, the determination is easy.If the tracer component is contained by the composition analysis of the glass defect, the location of the molten cast refractory containing the detected tracer component is the source. It can be identified. Conversely, if the tracer component is not contained at this time, it can be determined that a portion other than the molten cast refractory containing the tracer component is a glass defect source.

  Next, the case where the used glass material contains a tracer component will be described. In this case, since the tracer component is always detected, it is important how much the tracer component is detected by the composition analysis of the glass defect.

  If the tracer component is detected, but the detected amount is not different from the composition ratio of the glass material used, it is determined that a place other than the molten cast refractory containing the tracer component is a glass defect source. be able to. Also, when the detected amount is sufficiently large exceeding the composition ratio of the glass material used (for example, clearly when a difference of 1% by mass or more occurs), the molten cast refractory containing the tracer component It is possible to specify that a place composed of objects is a generation source. Thus, when the tracer component is contained in the glass material, analysis and determination can be facilitated by increasing the content of the tracer component contained in the molten cast refractory.

  Next, the molten cast refractory suitable for the glass defect generation source identifying method of the present invention will be described.

  The molten cast refractory of the present invention is an alumina / zirconia / silica molten cast refractory, an alumina melt cast refractory and a zirconia melt cast refractory, each comprising the above-described components, Each of these components will be described below. In addition, in this specification, content of a component is with respect to a refractory, and "%" means the mass%.

  First, each component of the alumina / zirconia / silica fusion cast refractory (hereinafter referred to as AZS fusion cast refractory) of the present invention will be described.

The Al ₂ O ₃ component in the AZS molten cast refractory is an important component along with ZrO ₂ in the component constituting the crystal structure of the refractory, and constitutes a corundum crystal and is composed of ZrO ₂ with respect to the molten glass. Next, it shows strong corrosion resistance and does not show transformation expansion like ZrO ₂ . The blending amount is preferably in the range of 45 to 70%. If it exceeds 70%, the amount of the matrix glass phase decreases, and mullite (3Al ₂ O ₃ .SiO ₂ ) is likely to be formed, so that the refractory cannot be produced without cracks. On the other hand, if the amount is too small, such as less than 45%, the amount of the matrix glass phase increases, so that the glass tends to exude.

The ZrO ₂ component in the AZS molten cast refractory has a strong resistance to erosion of the molten glass and is contained as a main component of the refractory. From this point of view, it is better, but in the present invention, if the ZrO ₂ content increases, the transformation expansion amount of ZrO ₂ and the stress accompanying it become too large, and the matrix glass phase cannot absorb the volume change. This makes it difficult to produce refractories without cracks. Moreover, when there are too few, the corrosion resistance with respect to a molten glass will become scarce. Therefore, the blending amount of the ZrO ₂ component is preferably in the range of 14 to 45%.

The SiO ₂ component is an important component that determines the characteristics as a main component constituting the matrix glass phase. The blending amount is preferably in the range of 9 to 15%. If it is less than 9%, the amount of the matrix glass phase decreases, and the matrix glass phase cannot absorb the volume change of ZrO ₂ , and it becomes difficult to produce the refractory without cracking. On the other hand, if it exceeds 15%, the amount of the matrix glass phase increases, so that the glass tends to exude.

The alkali components of Na ₂ O and K ₂ O are important components for adjusting the relationship between the temperature and viscosity of the matrix glass phase. If the total content exceeds 1.8%, the glass tends to ooze out. On the other hand, if the total amount is less than 0.8%, the viscosity of the matrix glass phase becomes too high and at the same time mullite is generated, so that the refractory cannot be manufactured without cracks.

Then, in the present invention, as a tracer component to identify a glass defect source are those containing at least one Cs ₂ O and SrO. Here, the above-mentioned compound was selected as the tracer component because when the matrix glass is exuded and mixed into the molten glass material, it can be sufficiently dissolved in the matrix glass and transferred to the glass material side. Because.

At this time, these Cs ₂ O, SrO, BaO and ZnO components have a total amount including Na ₂ O and K ₂ O, that is, a total amount of Na ₂ O, K ₂ O, Cs ₂ O and SrO is 2%. The Cs ₂ O and SrO components are 0.2% or more. When the tracer component is less than 0.2%, the detection performance is deteriorated, and it is difficult to specify the glass defect source.

  Other components may be contained in a slight amount to the extent that they do not impair the object effects of the present invention, but it is desirable to limit them to a small amount as much as possible.

For example, Fe ₂ O ₃ , TiO ₂ , CaO, and MgO are mixed as impurities of industrial raw materials and should be as little as possible, but the total amount as an industrial range is 0.05 to 0.4%. Even if it is contained within the range, it does not affect its properties.

  Next, each component of the alumina melt cast refractory of the present invention will be described.

Al ₂ O ₃ component as alumina fusion cast refractory is an important component in the components constituting the crystal structure of the refractory, BetaAl ₂ produced reacts with alpha Al ₂ O ₃ (corundum crystals) and alkali It has a crossed structure of O ₃ crystals. It exhibits strong corrosion resistance against molten glass and does not exhibit transformation expansion. The blending amount is preferably in the range of 94 to 98%. If it exceeds 98%, the βAl ₂ O ₃ crystal phase is reduced and cracking easily occurs. On the other hand, if the amount is too small, such as less than 94%, the βAl ₂ O ₃ crystal phase increases, the porosity becomes several percent or more, and the corrosion resistance against molten glass deteriorates.

SiO ₂ is an essential component for forming a matrix glass that relieves stress generated in the refractory. In order to obtain a refractory having a practical size without cracks, SiO ₂ needs to be contained in an amount of 0.1% or more in the refractory, and is preferably contained in an amount of 0.5% or more. However, when the content of the SiO ₂ component is increased, the corrosion resistance is reduced. Therefore, in the present invention, SiO ₂ is contained in the refractory within a range of 0.1 to 1.0%.

The alkali components of Na ₂ O and K ₂ O are important components that react with Al ₂ O ₃ to form βAl ₂ O ₃ crystals. If the total content exceeds 4.8%, the βAl ₂ O ₃ crystal phase increases, the porosity becomes several percent or more, and the corrosion resistance to the molten glass deteriorates. On the other hand, if the total amount is less than 1%, the βAl ₂ O ₃ crystal phase is reduced and cracking is likely.

Then, in the present invention, as a tracer component to identify a glass defect source are those containing Cs ₂ O, SrO, at least one of BaO and ZnO. Here, the above compounds were selected as the tracer component because the tracer component and Al ₂ O ₃ reacted to form βAl ₂ O ₃ and a matrix glass composition, and when in contact with molten glass at a high temperature, these were in a molten state. This is because it can be mixed into the glass material and transferred to the glass material side.

At this time, these Cs ₂ O, SrO, BaO and ZnO components are the total amount including Na ₂ O and K ₂ O, that is, the total of Na ₂ O, K ₂ O, Cs ₂ O, SrO, BaO and ZnO. The amount is 5% or less, and Cs ₂ O, SrO, BaO and ZnO components are contained in an amount of 0.2% or more. When the tracer component is less than 0.2%, the detection performance is deteriorated, and it is difficult to specify the glass defect source.

  Other components may be contained in a slight amount to the extent that they do not impair the object effects of the present invention, but it is desirable to limit them to a small amount as much as possible.

For example, Fe ₂ O ₃ , TiO ₂ , CaO, and MgO are mixed as impurities of industrial raw materials and should be as little as possible, but the total amount as an industrial range is 0.05 to 0.4%. Even if it is contained within the range, it does not affect its properties.

  Next, each component of the zirconia melt cast refractory will be described.

ZrO ₂ has strong resistance to erosion of molten glass and is contained as a main component of the refractory. Therefore, it the content of ZrO ₂ is large becomes excellent corrosion resistance against molten glass in the refractory, in zirconia fused cast refractories, in order to obtain sufficient corrosion resistance against molten glass, the ZrO ₂ The content is 88% or more.

On the other hand, if the content of ZrO ₂ is more than 97%, the amount of matrix glass becomes relatively small and it becomes impossible to absorb the volume change caused by the transformation of the baderite crystal, making it difficult to obtain a refractory without cracks. turn into. Therefore, in the present invention, ZrO ₂ is contained in the refractory in the range of 88 to 97%.

SiO ₂ is an essential component for forming a matrix glass that relieves stress generated in the refractory. In order to obtain a refractory having a practical size without cracks, this SiO ₂ needs to be contained in the refractory in an amount of 2.4% or more, preferably 5.0% or more. However, when the content of the SiO ₂ component is increased, the corrosion resistance is reduced. Therefore, in the present invention, SiO ₂ is contained in the refractory in a range of 2.4 to 10.0%.

Al ₂ O ₃ has an important role of adjusting the relationship between the temperature and viscosity of the matrix glass and has the effect of reducing the concentration of the ZrO ₂ component in the matrix glass. In order to suppress the formation of crystals such as zircon (ZrO ₂ · SiO ₂ ) in the matrix glass using this effect, the Al ₂ O ₃ component content needs to be 0.4% or more. Moreover, in order to maintain the viscosity of the matrix glass in the crystal transformation temperature range of the bedelite crystals as moderate, the Al ₂ O ₃ component content needs to be 3.0% or less. Therefore, in the present invention, Al ₂ O ₃ is contained in the refractory in the range of 0.4 to 3%.

If the Al ₂ O ₃ component is more than 3%, the viscosity of the matrix glass is increased, and the Al ₂ O ₃ component tends to react with SiO ₂ to produce mullite. Simultaneously with the decrease, the precipitated mullite crystal increases the viscosity of the matrix glass, resulting in residual volume expansion. When this residual volume expansion accumulates due to thermal cycling, cracks occur in the refractory, and the stability of the heat cycle is inhibited, so precipitation of mullite into the matrix glass is suppressed, and the cumulative tendency of residual volume expansion is noticeable. In order to decrease, the content of the Al ₂ O ₃ component is preferably 2% or less.

The alkali components of Na ₂ O and K ₂ O are important components for adjusting the relationship between the temperature and viscosity of the matrix glass phase. If the total content exceeds 0.8%, the glass tends to ooze out. On the other hand, if the total amount is less than 0.1%, the viscosity of the matrix glass phase becomes too high to produce a refractory without cracks.

Then, in the present invention, as a tracer component to identify a glass defect source are those containing Cs ₂ O. Here, the above-mentioned compound was selected as the tracer component because when the matrix glass is exuded and mixed into the molten glass material, it can be sufficiently dissolved in the matrix glass and transferred to the glass material side. Because.

At this time, these Cs ₂ O components include a total amount including Na ₂ O and K ₂ O, that is, a total amount of Na ₂ O, K ₂ O and Cs ₂ O is 1% or less, and Cs ₂ O component is contained in an amount of 0.2% to 0.5%. When the tracer component is less than 0.2%, the detection performance is deteriorated, and it is difficult to specify the glass defect source.

  Other components may be contained in a slight amount to the extent that they do not impair the object effects of the present invention, but it is desirable to limit them to a small amount as much as possible.

For example, Fe ₂ O ₃ , TiO ₂ , CaO, and MgO are mixed as impurities of industrial raw materials and should be as little as possible, but the total amount as an industrial range is 0.05 to 0.4%. Even if it is contained within the range, it does not affect its properties.

  Each of the above-mentioned molten cast refractories is manufactured by uniformly mixing powder raw materials so as to have the above blending ratio, melting this with an arc electric furnace, pouring the molten raw material into a sand mold or a graphite mold, and cooling. Is done. This refractory is expensive because it takes a large amount of energy when melted. However, since the crystal structure obtained is dense and the size of the crystal is large, the refractory is superior in corrosion resistance stability to the sintered refractory. In addition, the heating at the time of melting is performed by bringing a graphite electrode and raw material powder into contact with each other and energizing the electrode.

  The refractory material thus obtained exhibits excellent corrosion resistance with respect to molten glass, and is suitable for a furnace material for a glass melting furnace used when producing a glass product such as a plate glass.

  The glass melting kiln of the present invention is manufactured using the above-described molten cast refractory of the present invention, and may be manufactured using the molten cast refractory of the present invention as a lining furnace material.

  Moreover, in the production of this glass melting furnace, as described above, the glass melting furnace is divided into arbitrary block units, and is constructed using a molten cast refractory material having a different tracer component for each block as a lining furnace material. Is preferred. At this time, a conventionally used molten cast refractory material that does not contain a tracer component may be used for a block that is not considered to be a source of glass defects.

  At this time, how to divide the block unit and which type of molten cast refractory to use for each block unit predicts the flow path of the glass melt at the design stage and efficiently generates glass defects. It is preferable to determine such that the source can be identified.

  EXAMPLES The alumina / zirconia / silica fusion cast refractory of the present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
The raw materials of each component are homogeneously mixed so as to have the composition shown in Table 1, and this is melted by an arc electric furnace, and the molten raw material is poured into a graphite mold and cooled to have a zirconia content of 32% class. An AZS electroformed brick was obtained. This contains 0.43% of Cs ₂ O as a tracer component.
A 10 mm × 20 mm × 120 mm rectangular parallelepiped sample was cut out from the obtained electrocast brick, and eroded in a 1500 ° C. platinum crucible in which plate glass was melted for 72 hours, and the amount of erosion of the electroformed brick at that time was measured. While measuring, the Cs ₂ O content in the glass near the brick was examined. Separately from this, a 30 mm (diameter) × 30 mm (height) sample was cut from the obtained electrocast brick, and the amount of glass exudation after heating for 16 hours at 1500 ° C. in an electric furnace was determined. The results are shown in Table 1.

(Example 2)
As a tracer component, electrocast brick was cast in the same manner as in Example 1 except that 0.48% of SrO was contained instead of Cs ₂ O, and the amount of erosion by glass, SrO content and glass exudation amount were determined. Examined. The results are shown in Table 1.

Example 3
A tracer component having a Cs ₂ O content of 2.1% was cast in the same manner as in Example 1. Similarly to Example 1, the amount of erosion by glass, the SrO content and the amount of glass exudation were examined, and the results are shown in Table 1.

(Comparative Examples 1-2)
The same operation as in Example 1 was performed for a normal AZS electroformed brick (Comparative Example 1) that does not contain Cs ₂ O and SrO at the same time as a tracer component, and a Cs ₂ O content of 0.19% (Comparative Example 2). Casted with. Similarly to Example 1, the amount of erosion by glass, the SrO content and the amount of glass exudation were examined, and the results are shown in Table 1.

* Brick erosion after erosion test:
Corrosion resistance is determined by measuring the amount of erosion after a 10 mm x 20 mm x 120 mm rectangular parallelepiped sample is cut from an ingot, suspended in a platinum crucible and immersed in a glass material at 1500 ° C for 48 hours. It was. The glass materials used here are SiO ₂ 72.5%, Al ₂ O ₃ 2.0%, MgO 4.0%, CaO 8.0%, Na ₂ O 12.5%, K ₂ O 0.8. % Composition.
* Tracer component content in glass near brick after erosion test:
In the said erosion test, the component of the glass of 0.5-1 mm away from the surface layer of the sample immersed in glass was measured using the electron microscope (SEM-EDX).
* Glass oozing amount: A cylindrical sample having a diameter of 30 mm and a height of 30 mm is cut out with a diamond core drill, and the dry mass (W1) and the underwater mass (W2) are measured by the Archimedes method. After holding this sample at 1500 ° C. for 16 hours in an electric furnace, it is taken out of the furnace and allowed to cool naturally outside the furnace. This sample is again measured for dry mass (W3) and underwater mass (W4) by Archimedes method. Using the measured value thus obtained, the calculation was performed by the following equation (1).
Glass exudation amount = [(W3-W4) / (W1-W2) -1] × 100% (1)

As a result, Example 1 and Example 2 were able to detect Cs ₂ O and SrO from the glass in the vicinity of the furnace material after a long-term erosion test at 1500 ° C. for 72 hours, resulting in a glass defect. In addition, it was confirmed that the tracer component was detected. Moreover, it was confirmed that the corrosion resistance and the glass leaching test result by the erosion test are not significantly different from the bricks (Comparative Example 1) that are currently used. Also in Example 3, Cs ₂ O in the glass near the furnace material after the erosion test was sufficiently detected as 1.5%. However, in Example 3, the corrosion resistance and the glass exudation amount in the erosion test are large, and when such a material is used in a glass kiln, there is a possibility that the product is adversely affected.
On the other hand, in Comparative Example 2, the Cs ₂ O content was 0.19%, but Cs ₂ O was not detected in the glass near the furnace material after the erosion test.

  From the above, it was possible to easily and directly identify the glass defect source by the glass defect source identification method of the present invention.

  The glass defect generation source identifying method of the present invention can be used in the field of manufacturing glass products using a glass melting kiln. In addition, the molten cast refractory of the present invention and the glass melting furnace using the same are suitable for performing the glass defect generation source identifying method of the present invention, but in the production of glass products not performing this identifying method. It can also be applied to a glass melting furnace.

Claims (7)

In chemical composition by mass%, the Al ₂ O ₃ 45 to 70%, a ZrO ₂ 14 to 45%, the SiO ₂ comprises 9-15%, the total amount of _{Na 2 O, K 2 O,} Cs 2 O and SrO Is 2% or less, and contains 0.2-2% of at least one tracer component selected from Cs ₂ O and SrO. Alumina / zirconia / Silica fusion cast refractory. Chemical composition is mass%, contains ZrO ₂ 88-97%, SiO ₂ 2.4-10.0%, Al ₂ O ₃ 0.4-3%, Na ₂ O, K ₂ O and Cs ₂ The total amount of O is 1% or less, and contains 0.2 to 0.5% of a tracer component of Cs ₂ O. . A glass melting kiln characterized by using the molten cast refractory according to claim 1 or 2 as a lining furnace material. The glass melting kiln using the molten cast refractory according to claim 1 or 2, wherein the glass melting kiln is divided into arbitrary block units depending on the constituent parts, and contains different tracer components for each block unit. . A step of constructing a glass melting kiln using the molten cast refractory according to claim 1 as a lining furnace material;
Melting the glass material in the glass melting furnace, molding the molten glass material, and manufacturing a glass product;
Extracting a glass defect from the glass product, analyzing the component composition to determine the position of the glass defect source in the glass melting furnace, and
A glass defect source identifying method characterized by comprising: 6. The method for identifying a glass defect source according to claim 5 , wherein a tracer component contained in the molten cast refractory is not contained in the molten glass material. The glass defect generation source according to claim 5 or 6, wherein a constituent portion of the glass melting furnace is divided into block units, and a molten cast refractory containing different components as the tracer component is used for each block unit. Identification method.